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Diagonalization of א0-Forms

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Part of the book series: Progress in Mathematics ((PM,volume 1))

Abstract

In this chapter we shall prove that א0-dimensional sesquilinear spaces are orthogonal sums of lines and planes and we characterize the cases where a decomposition into mutually orthogonal lines is impossible. The problem of “normalizing” bases brings us to stability and the beginner is confronted with the first Ping-Pong style proof with its characteristic back-and-forth argument (Theorem 2). These matters are basic and their knowledge is tacitly assumed in the rest of the book.

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References to Chapter II

  1. W. Baur and H. Gross, Strange inner product spaces. Comment. Math. Helv. 52 (1977) 491–495.

    Article  Google Scholar 

  2. W. Bäni, Sesquilineare Formen und lineare Topologien. Ph.D. Thesis, University of Zurich (1975).

    Google Scholar 

  3. W. Bäni, Linear Topologies and Sesquilinear Forms. Comm. in Algebra, 14 (1977) 1561–1587. (Neither of [2] or [3] is a subset of the other.)

    Article  Google Scholar 

  4. C. Everett and H. Ryser, Rational vector spaces. Duke Math. J. 16 (1949) 553–570.

    Article  Google Scholar 

  5. J. P. Gram, Ueber die Entwicklung reeller Funktionen in Reihen mittelst der Methode der kleinsten Quadrate. J. reine angew. Math. 94 (1883) 41–73.

    Google Scholar 

  6. H. Gross, On Witt’s theorem in the denumerably infinite case. Math. Annalen 170 (1967) 145–165.

    Article  Google Scholar 

  7. H. Gross, Der euklidische Defekt bei quadratischen Räumen. Math. Ann. 180 (1969) 95–137.

    Article  Google Scholar 

  8. H. Gross and E. Ogg, Quadratic Spaces with Few Isometries. Comment. Math. Helv. 48 (1973) 511–519.

    Article  Google Scholar 

  9. H. Gross and E. Ogg, Quadratic forms and linear topologies. On completions. Ann. Acad. Sci. Fenn. A.I. 584 (1975) 1–19.

    Article  Google Scholar 

  10. P. Hafner, Zur Berechnung endlicher euklidischer Defekte in quadratischen Räumen. Comment. Math. Helv. 45 (1970) 135–151.

    Article  Google Scholar 

  11. I. Kaplansky, Forms in infinite-dimensional spaces. Anais da Academia Brasileira de Ciencias, vol. 22 (1950) 1–17.

    Google Scholar 

  12. G. Maxwell, Classification of countably infinite hermitean forms over skewfields. Amer. J. Math. 96 (1974) 145–155.

    Article  Google Scholar 

  13. A. Meyer, Ueber die Auflösung der Gleichung ax2 +by2 +cz2 +du2 +ev2 = 0 in ganzen Zahlen. Vierteljahrs. Naturforsch. Gesellsch. Zürich 29 (1884) 220–222.

    Google Scholar 

  14. E. Ogg, Die abzählbare Topologie und die Existenz von Orthogonalbasen in unendlichdimensionalen Räumen. Math. Ann. 188 (1970) 233–250.

    Article  Google Scholar 

  15. E. Schmidt, Zur Theorie der linearen und nichtlinearen Integralgleichungen. Math. Ann. 63 (1907) 433–476.

    Article  Google Scholar 

  16. G. L. Watson, Integral quadratic forms. Cambridge Univ. Press (1960).

    Google Scholar 

References to Appendix I

  1. A. A. Albert, Structure of Algebras.(3rd print. of rev. ed.) AMS Coll. Publ. XXIV, NY 1968.

    Google Scholar 

  2. P. M. Cohn, Free Rings and their Relations. Academic Press London 1971.

    Google Scholar 

  3. A. Fröhlich, Quadratic forms à la local theory. Proc. Camb. Phil. Soc. 63 (1967) 579–586.

    Article  Google Scholar 

  4. H. Glauser, Schiefkörper mit Anordnung und Involution. Master’s Thesis, University of Zurich 1972.

    Google Scholar 

  5. H. Gross and H.R. Fischer, Nonreal fields k and infinite dimensional k-vector spaces. Math. Ann. 159 (1965) 285–308.

    Article  Google Scholar 

  6. I. Kaplansky, Forms in infinite-dimensional spaces. Anais Acad. Bras. Ci 22 (1950) 1–17.

    Google Scholar 

  7. M. Krasner, Review on a paper by I. Kaplansky. Math. Rev. AMS vol. 15 (1954) p. 500.

    Google Scholar 

  8. T. Y. Lam, The algebraic theory of quadratic forms. W.A. Benjamin Inc., Reading, Massachusetts 1973.

    Google Scholar 

  9. S. Lang, On quasi algebraic closure. Ann. of Math. 55 (1952) 373–390.

    Article  Google Scholar 

  10. G. Maxwell, A note on Artin’s Diophantine Conjecture. Canad. Math. Bull. 13 (1970) 119–120.

    Article  Google Scholar 

  11. M. Nagata, Note on a paper of Lang concerning quasi algebraic closure. Mem. Univ. Kyoto Ser. A 30 (1957) 237–241.

    Google Scholar 

  12. O. T. O’Meara, Introduction to quadratic forms. Grundlehren Bd. 117 Springer Berlin 1963.

    Book  Google Scholar 

  13. O. Ore, Linear equations in non-commutative fields. Ann. of Math. 32 (1931) 463–477.

    Article  Google Scholar 

  14. O. Ore, Theory of noncommutative polynomials. Ann. of Math. 34 (1933) 481–508.

    Article  Google Scholar 

  15. A. Pfister, Letter to the author, dated 9.7.1968. (It contains a detailed proof for the fact that k̇/k̇2 is infinite when k = ℚ̄(√2), ℚ̄ the quadratic closure of ℚ.)

    Google Scholar 

  16. A. Pfister, Systems of quadratic forms. Bull.Soc.Math. de France Mémoire 59 (1979).

    Google Scholar 

  17. G. Terjanian, Dimension arithmetique d’un corps. J. Algebra 22 (1972) 517–545.

    Article  Google Scholar 

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Gross, H. (1979). Diagonalization of א0-Forms. In: Quadratic Forms in Infinite Dimensional Vector Spaces. Progress in Mathematics, vol 1. Birkhäuser, Boston, MA. https://doi.org/10.1007/978-1-4899-3542-7_3

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  • DOI: https://doi.org/10.1007/978-1-4899-3542-7_3

  • Publisher Name: Birkhäuser, Boston, MA

  • Print ISBN: 978-0-8176-1111-8

  • Online ISBN: 978-1-4899-3542-7

  • eBook Packages: Springer Book Archive

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